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GREATER KANDY WATER
SUPPLY PROJECTPRESENTATION
TO
GREATER COLOMBO WATER REHABILITATION PROJECT
STAFF
THINGS TO DO IN WATER RETAININGRESERVOIR CONSTRUCTION
18THSEPTEMBER 2009
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INTRODUCTION
Construction Backwash Recovery Facility
This Is not a presentation on Design or Construction of Water RetainingStructures
Very briefly few problems encountered in the administration of theabove contract will be discussed
Insurance Day works Attendance to contractor Payment for preparation of Method Statements Water Bar in Concrete joints Shoring during Excavation
Rock Blasting Laying of Hume pipes Use of Collars Marker Tapes Drawing Errors Safety Officer Quality Control Formworks
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INSURANCE
Contractor shall take full responsibility for care of works andmaterials and plant from commencement until hand over
Provisional sum or to be quoted in BOQ Employers risks Insurance of works and contractors equipment Scope of cover
Shall be in the joint names of the contractor and employer
Shall cover employer and contractor against all loss or damage
from what ever cause arising until take over
Third party Insurance Contractor shall insure in the jointnames of employer and contractor
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DAY WORKS
When ever necessary any varied work may beexecuted on a day work basis on receivinginstruction from the Engineer
Normally day work schedules for labour, materialsand construction plant is included in the BOQ
in the NWS&DB it has own standard ratesestablished for Day works. These rates will coveroverheads and profit.
Generally in most of the other contracts contractoris required to enter the rates for labour,equipments etc. and the contractor will not beentitled to overheads or profits.
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INSTALLATION OF WATER BARS
In all large concrete water retaining structure it isnecessary to provide construction joints as it maynot be possible to complete concreting in onepouring of any base or wall.
It is necessary to make the joints watertight. It isthe normal practice to install Water Bars at thejoint to make these watertight.
General and particular specifications gives the
approved specifications for water Bars
Methods statement should describe and explainthe placing of Water Bars
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USE OF BONDING AGENT
Bonding agents are classified in tocategory of construction chemicals
These are used to bond two surfaces ofconcrete
Method statement should Cleary state theuse of Bonding Agent
These are important points to look for
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Applying Bonding Agent in concrete surfaces
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SHORING
Shoring is required where ever deep excavations
are carried out.
It is found that the specification of shoring isincluded in the specification, but not clearly
referred in BOQ
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Inadequate Protective System
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Properly Shored Trenches
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ROCK BLASTING
Proper planning of supply of BlastingMaterials and detonators required.
Safety Measures
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MARKER TAPE
Relevant Specification
Including as a BOQ item
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SAFETY AT SITE
PPE for workers
Ensuring facilities for prevention ofaccident
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Inappropriate Safety tools
No goggles .?No helmets..?
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